Miley Cyrus' younger sister marked her 13th birthday on Tuesday (08Jan13) by calling for an end to horse and carriage rides from New York City's Central Park.
Noah Cyrus marked her special day by urging fans to donate $13 to animal-advocacy group New Yorkers for Clean, Liveable & Safe Streets (NYCLASS) or sign a petition supporting the axe of the cruel tourist trade.
The child actress tells the New York Daily News, "When I first learned about the inhumane treatment of horses in New York City, I was devastated. As a rider, I would never put my horse at risk in dangerous midtown traffic."
NYCLASS lead organiser Allie Feldman adds, "When Noah turned 13, she and her mother got in touch with us and decided that they wanted to try and raise awareness as part of her birthday. We think it's great she's become this mini-horse activist at such a young age."
The birthday girl spent the day with her sister Miley - and the singer/actress shared photographs from the celebrations with her fans on Twitter.com.
The siblings are seen cuddling up to a cardboard cut-out of One Direction star Harry Styles in one image, with Miley declaring, "All noah cyrus wants for her BIRFFFDAY (sic) is harry styles."
She later added, "In no way do I want Harry. No offense (sic)... I'm happily engaged. Just got saucy with a cardboard cut out."